Circuit for synchronizing watches driven by a coil-magnet system

ABSTRACT

A circuit arrangement for electrically driven watches wherein the mechanical vibrator is driven by a mechanical or electronic switch which can be synchronized by the divided frequency of a quartz oscillator.

ited States Patent Keller Nov. 25, 1975 [54l CIRCUIT FOR SYNCHRONIZING 3,576.455 4/l'-)7l lngenito..... 58/23 R WATCHES DRIVEN y A CO[L MA'GNET 3.597.634 8/l97l Flaig 53/28 X SYSTEM 3,714.77 Z/l973 Dtershock fa /2H B 3.745 76() 7/1973 Keeler 58/28 R [75] Inventor: Hans Keller, Gundelfingen, 3.766.454 I0/I973 Berney 5 /23 AC Germany 3.798,52l 3/1974 Berney.... 58/23 x 3.805 l79 4/1974 Berney.... 33l/ll6 M Asslgnee: l Industries, New Y 3.806.781 4/1974 Berney 58/23 A N.Y. 3.8l8,376 6/l974 Keller et ul. 58/23 A [22] Filed: Jan. 3], 1974 [211 App NO 438 157 Primary Examinerloseph W. Hartary Assistant ExaminerU. Weldon Attorney, Agenr. 0r Firm-John T. OHalloran; [30] Foreign Application Priority Data Menotti J. Lombardi, Jr.

Feb. 24, 1973 Germany H 230929l [52] U.S. Cl. 58/28 R; 58/23 A; 331/116 M [57] ABSTRACT [51] Int. Cl. G04C 3/04; H03B 5/30 [53] Field of Search- 58/23 23 A, 23 23 D' A circuit arrangement for electrically driven watches 58/23 TF 23 V' 2 R 2 A 2 B 2 D- 2 wherein the mechanical vibrator is driven by a me- 331/116 318/119 m6 127 129 chanical or electronic switch which can be synchro nized by the divided frequency of a quartz oscillator.

[56] Relerences Cited UNITED STATES PATENTS l 6 Drawmg F'gures 3,451,210 6/1969 Helterline. Jr, et al. 58/28 R 4 f H MAGNET TYPE l l l l T2 R4 BALANCE SYSTEM QUARTZ OSCILLATOR T5 AND FREQUENCY DIVIDER E I L FI J T3 U.S. Patent Nov. 25, 1975 Sheetlof4 3,921,386

T=T AT1- ATZ ATZ Fig.1

.N N H .INIHV I v M! INI II I I'll Ill-l N H v Fig.2

US. Patent Nov. 25, 1975 Sheet 3 of4 3,921,386

Fig.3

U.S. Patent Nov. 25, 1975 Sheet40f4 3,921,386

U UB 2+ I D I MAGNIET m T2 2 3 "F NCE 3 BALANCE QUARTZ SYSTEM 7 D SYSTEM OSCILLATOR QUARTZ N R OSCILLATOR FREQUENCY AND R DNIDER FREQUENCY K DIVIDER K o H I l I Tl J J L T1 i O- i 0- Fig.4 Fig.5

4+ I f H MAGNET m T2 R SYSTEM o fi ron T5 AND FREQUENCY DIVIDER 1,

R2 R1 []R3 I I FL I '43 Fig.6

CIRCUIT FOR SYNCHRONIZING WATCHES DRIVEN BY A COIL-MAGNET SYSTEM BACKGROUND OF THE lNVENTlON Stepping mechanisms used predominantly as electromechanical transducers for utility quartz clocks and quartz watches, are relatively susceptible to shocks. in this respect. electromagnetically driven balance or tuning fork systems exhibit substantially better behaviour. Also for production-technical reasons a quartz watch which makes use of an already existing calibre, merely by employing commercially available types of quartz oscillators and frequency dividers, is improved to the standard of a utility quartz watch in that the vibrator frequency of the already existing calibre is synchronized by the divided quartz oscillator frequency.

in this connection, it would be of particular advantage to have a synchronizing method suitable for conventional types of contact-making clocks as well as to electronically driven clocks or watches employing a single-or two-coil system. One such method of synchronization is proposed by the present invention.

Considering that the vibration frequency of a balance depends upon, among other things the kind of energy supplied, this actually disadvantageous property can be utilized for the synchronization of an electromagnetically driven watch vibrator.

Thus it is known eg from the German Offenlegungsschrift 2 O] l 233 (corresponding to the Swiss Pat. No. 526 150) that a simple singleor two-coil balance system automatically driven by a corresponding circuit, can be synchronized when applying, in addition to the main driving pulse, one or more timely displaced and thus adjacent auxiliary driving pulses which are triggered by the synchronizing signal taking place several times during one balance vibration, i.e. the frequency of the synchronizing pulses is several times higher than that of the balance. in this method, however, the balance system is unnecessarily supplied with more energy than necessary by the one or more auxiliary driving pulses, so that the amplitude of vibrations of the balance is increased, the battery is additionally loaded, and unwanted transients are likely to appear during the control.

On the other hand, it has become known from the Swiss Pat. No. 496 276 that the vibration frequency of an electro-magnetic type of balance system can be better synchronized when supplying the drive coil with two successively following driving current pulses with a constant total energy content, of which the one is effected prior to and the other one subsequently to the reference position of the balance, where the vibration frequency of the balance as a function of the synchronizing signal, is changed upon variation of the relative amounts of the two pulses. For realizing this method, however, there is proposed an expensive circuit employing a bridge or parallel push-pull stage for driving the electro-magnetic balance system, and with two moving coils which cannot be connected directly to one pole of the battery as is desirable in particular with a view to realizing such circuits in accordance with the known monolithic integration technique. Apart therefrom, the bridge or parallel push-pull circuit is incapable of maintaining the vibrations of the balance without the circuit generating the synchronizing signal.

Moverover. the entire circuitry of this conventional kind operates on the principle of phase comparison between the balance vibration frequency and the frequency of the synchronizing signal. For this purpose it comprises several multivibrator stages and one sawtooth generator for achieving the phase comparison. This adds towards the aforementioned expensiveness. In addition thereto, the known circuit is tailored to a special kind of coil and magnet system employing two concentrical flat coils and one pair of magnet poles in the direction of vibration, so that in the coil limbs arranged in front and behind the reference position, there is generated per semi-vibration of the balance one positive and one negative pulse, from which there compulsorily results the aforementioned use of a bridge or parallel push-pull circuit.

Moreover, from the Swiss Pat. No. 528 770 (corresponding to the US. Pat. No. 3,648,453) there has become known a synchronizing method for clock vibrators likewise operating with the aid of a phase comparison. Here, too, the frequency of the synchronizing signal is several times higher than the frequency of the vibrator. Also. there are used merely needle-shaped synchronizing signals which only serve to stimulate the circuit maintaining the vibrations, to provide the driving current pulse, There is also provided for the case where, by a second needle-shaped synchronizing pulse which is phase-shifted with respect to the tripping necdle-shaped synchronizing pulse, the transmission of the driving current pulse is terminated again.

This known synchronization method like-wise calls for an extensive electronic circuit, in particular for the derivation of the setting signal by means of a phase comparison, as well as for two two-coil systems of which the one serves as the driving system and the other one as the pick-up system for the phase comparison.

For overcoming the disadvantages of these conventional arrangements, the applicant, in its earlier German Patent Application P 22 10 542.6 has already proposed choosing the vibration frequency of the balance, as a function of the sign of the voltage as induced in the driving coil of the magnet system, with respect to the polarization of the supply voltage source and with respect to the conductivity type of the driving transistor of the automatic driving circuit, to be either somewhat higher or somewhat lower than half the frequency of the synchronizing signal, periodically once per semivibration of the balance, a current path of the automatic driving circuit in such a way that the energy con tent of the main driving pulse is more reduced, the more the vibration frequency of the balance deviates from half the synchronizing frequency, and to dimension the automatic driving circuit in such a way that upon reduction of the energy of the main driving pulse there is automatically generated an auxiliary driving pulse having the same polarity as the main driving pulse, and that as a function of the energy content of the main driving pulse, the charge of a capacitor as contained in the automatic driving circuit, is varied in the sense of keeping constant the entire energy content of both driving current pulses.

Finally, and with a view to providing synchronization universally applicable to contact-making clocks and electronic clocks (watches), a synchronization method has been proposed by the applicant in its earlier German Patent Application P 22 38 4050, according to which the driving coil is pulsewisely switched on during respectively the back and forth movement of the vibrator via either a mechanical or electronic switch for maintaining the vibrations. with the proposed arrangement being such that the forward driving pulse and the backward driving pulse are applied to the driving coil either at a different spacing from the rest position of the vibrator before or after the rest position of the vibrator or at a same or different spacing before and after the rest position of the vibrator. and that the driving energy, as a function of the deviation of the divided quartz oscillator frequency from the frequency of the mechanical vibrator or from an integral part or multiple of this frequency. is divided between the forward and the backward driving pulse.

Accordingly, the arrangement proposed in this earlier application simplifies the aforementioned conventional types of synchronization arrangements in that the synchronization does not act upon each individual pulse of the induced voltage separately. but that both the forward and the backward driving pulses are used in mutual dependency for effecting the synchronization.

The known synchronization arrangements and the synchronization arrangements according to the applicants two earlier proposals, all have the common disadvantage of having a restricted synchronizing range because. for example. the displacement (shifting) of the center axes of both the driving coil and the magnet system which is possible in some of these synchronization methods. cannot be made arbitrarily large. This would cause the efficiency to become too small in the case of low amplitude vibrations occurring in the starting case.

Starting out. but partly also deviating from the known prior art referred to hercinbefore. the present invention relates to the synchronization mechanical vibrators in utility clocks. in particular watches driven via a coilmagnet system. by means of a synchronizing signal whose frequency corresponds to the frequency of a quartz oscillator divided to the order of the vibrator frequency. The driving coil, each time during the forward and backward movement of the vibrator, is pulsewisely switched on via a mechanical or electronic switch for maintaining the vibrations. and is thus being passed through through by one or more driving current pulses in the same effective direction. with the frequency of the mechanical vibrator being affected by the synchronizing signal in that the one or more driving current pulses is (are) applied in dependence upon the frequency or phase difference either before and/or after the mechanical vibrator has assumed its rest position.

SUMMARY OF THE INVENTION It is the object of the invention to provide a synchronizing arrangement which overcomes the aforementioned disadvantages and increase synchronizing range. This is accomplished in that at least temporarily and in addition to the one or more driving current pulses. at least one damping current pulse is applied to the driving coil in a direction of effect which is in opposition to that of the one or more driving current pulses. and that the current content and/or the time position of the one or more driving current pulses and damping current pulses is controlled with respect to the rest position of the mechanical vibrator as a function of or in dependence upon the phase difference either between the frequency of the mechanical vibrator and the frequency of the synchronizing signal or between an integral part or multiple of both frequencies.

This is based on the recognition that the mechanical vibrator system must be supplied with energy not only at fixed time positions. but that a withdrawal of energy at other fixed time positions leads to an expansion of the synchronizing range.

In further embodying the invention the one or more damping current pulses may be triggered during each complete or semi-vibration of the mechanical vibrator. On the other hand, synchronization may also be realized in such a way that the one or more damping current pulses are only triggered as the result of an external disturbance, hence in the case of a wristwatch. in response to a strong movement of the arm. the frequency or the phase position of the mechanical vibrator is varied in excess of a given threshold value.

For generating the one or more damping current pulses it has proved particularly suitable for a resistor and/or a diode and/or a transistor to be periodically connected in parallel with the driving coil, or for the driving coil to be periodically sh0rt-circuited Moreover. it may be of advantage to displace the rest position of the center axes of both the driving coil and the magnet system with respect to one another.

An arrangement which is particularly simple with respect to realization from the circuit-technical point of view. will result in cases where the synchronizing signal is rectangular. and where the pulse duty factor thereof is chosen in accordance with the smallest spacing in terms of time between the forward and the backward driving current pulse at the lowest amplitude of the mechanical vibrator. and. in further embodying the invention. the one or more damping current pulses are triggered during that particular period of time of the synchronizing signal which corresponds to the smallest spacing in terms of time between the forward and the backward driving current pulse at the lowest amplitude of the mechanical vibrator.

In regard to the above-mentioned case where the one or more damping current pulses are to be triggered only upon exceeding a given limit with respect to the frequency or phase shift and when employing the aforementioned rectangular synchronizing signal. it has proved to be particularly suitable, for controlling the damping current pulses, to use a second synchronizing signal with a shorter switch-on time which is independent of the synchronizing signal controlling the driving current pulses, but of the same frequency. i.e. in such a way that neither the one or more driving current pulses nor the one or more damping current pulses are triggered during both particular periods of time lying between the edges of the two synchronizing signals.

As regards enlarging the synchronizing range, the inventive arrangement can still be improved by designing the mechanical vibrator in such a way that its vibration frequency is dependent upon the amplitude of vibrations. In so doing, the mechanical vibrator. on one hand. may be designed to have such a frequencyamplitude dependence that the vibration frequency is increased as the amplitude of vibrations increases, and that by the one or more driving current pulses as occurring before the rest position of the vibrator. there is supplied more energy than by the one or more driving current pulses occurring after the rest position and, on

the other hand. however, may also be provided with such a frequency-amplitude dependence that the vibration frequency is reduced as the amplitude of vibrations increases, and that by the one or more driving current pulses as occurring after the rest position of the vibrator, there is applied more energy than by those occurring before the rest position.

The aforementioned setting of the pulse duty factor of the rectangular synchronizing signal in accordance with the smallest spacing as a function of time between the forward and the backward driving current pulse at the highest frequency of the mechanical vibrator can be carried out, for example, in a simple way by means of the already existing frequency divider, in that the pulse width of the output pulse of the frequency divider is coupled to the pulse width of the output pulses of one or more preceding divider stages via either a gate circuit or a flip-flop circuit, so that the output pulse of the frequency divider will no longer have a 1:] pulseinterval ratio, and that instead the pulse width will be determined by the absolute width of the output pulse of one or more preceding frequency-divider stages transmitted at the 1:1 pulse-interval ratio. According to a broad aspect of the invention there is provided a circuit for synchronizing watches driven by a coil-magnet system, by means of a synchronizing signal having a frequency which corresponds to the frequency of the divided output of a quartz oscillator, said circuit powered by a source of supply voltage having positive and negative poles, comprising: a source of a first synchronizing signal; a driving coil having first and second terminals, said first terminal coupled to the positive pole of said source; a contact having first and second terminals, said first terminal coupled to the second terminal of said coil; a first transistor having base, emitter and collector terminals, said base coupled to said first synchronizing signal, said emitter coupled to the zero point of the circuit and said collector coupled to the second terminal of said contact; a diode; and a first resistor coupled in series with said diode between said diode and said collector. the series combination of said first resistor and said diode coupled between the collectoremitter path of said first transistor and said positive pole, said series combination coupled in parallel with the series combination of said coil and said Contact.

Details of the inventive method and circuit arrangements for carrying out the method will now be explained in greater detail with reference to FIGS. 1 to 6 of the accompanying drawings, in which:

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 shows various shapes of curves relating to the physical facts of the case on which the invention is based,

FIG. 2 shows various shapes of curves for explaining the principle on which the invention is based,

FIG. 3 shows various shapes of curves for explaining the principle on which a further embodiment of the invention is based,

FIG. 4 shows a simple circuit arrangement for carrying out the inventive method in connection with a contact-making clock system,

FIG. 5 shows a further embodiment of the circuit arrangement according to FIG. 4, and

FIG. 6 shows a circuit arrangement for carrying out the inventive method by employing an electronic single-coil circuit for maintaining the vibrations of the mechanical vibrator.

DESCRIPTION OF THE PREFERRED EMBODIMENT in FIG. la the deflection of a mechanical vibrator is shown as a sinusoidal curve having the amplitude A. If the vibrator were to have no losses, the once excited vibration would be maintained unchanged. The undisturbed period of this mechanical vibration is indicated by T in FIG. la.

If now, in the case of magnet systems employing an odd number of magnetic pole pairs, and by the aforementioned parallel shift of both the coil axis and the magnet system axis, or in the case of magnet systems employing an even number of pairs of magnet poles by utilizing only one of the voltage pulses induced with the same sign, care is taken that the driving current pulses during the forward and the return movement, are effected asymmetrically in relation to the rest position of the vibrator, the period of vibration will change in accordance with the formula given in FIG. la.-

The actual vibration period T is composed of the sign-loaded sum of the undisturbed vibration period T and the times AT] and ATZ. Relative thereto, the time AT] indicates the time from the undisturbed zero-axis crossing to the point of intersection of both the zero axis and the tangent to the sinusoidal curve changed by the driving pulse N occurring after the rest position of the vibrator. While the time ATZ indicates the time between the next undisturbed zero-axis crossing and the point of intersection of the zero axis and the tangent to the sinusoidal curve changed by the driving pulse V as effected before the rest position of the vibrator, with this time thus having to be inserted in the aforementioned formula with a negative sign. The dot-anddashline extending horizontally through FlG.la is supposed to denote the parallel shift of the center axes of both the coil and the magnet system or the aforementioned asymmetry in the case of an even number of magnet pole pairs, respectively.

FIGS. lb and It show the pulses N, V of the induced voltage u, as effected asymmetrically in relation to the zero position of the mechanical vibrator, as well as the associated pulse current i flowing in the coil, both as a function of the time t.

FIG. 2a shows the course of time of the rectangular synchronizing signal, with the pulse duty factor thereof corresponding to the magnitude B/(A-l-B) or with the pulse-interval ratio thereof corresponding to the magnitude B/A. In this case the time B, as already mentioned hereinbefore, is equal to (or shorter than) that particular period of time corresponding to the smallest spacing of time between the forward and the backward driving current pulse at both the highest frequency and the smallest amplitude of the mechanical vibrator.

FIG. 2b shows the course of time of the timing current pulses, wherein V indicates the driving current pulse triggered before the vibrator reaches its rest position, and wherein N indicates the driving current pulse triggered after the vibrator has reached its rest position. For the sake of enabling a better understanding, FIG. 2b shows a case in which the mechanical vibrator is at the same frequency as the synchronizing signal, but is not affected by the latter owing to its phase position.

FIG. 20 shows the case where the frequency of the mechanical vibrator is in such a way reduced with respect to the frequency of the synchronizing signal. or has changed to such an extent in its phase position that the driving current pulse N. with respect to time. partly intersects with the pulse component of the synchronizing signal as positively shown in FIG. 2a. In the inventive manner energy so to speak. is withdrawn from the mechanical vibrator during the intersecting period owing to the fact that in the driving coil there is flowing a damping current pulse in a direction of effect which is in opposition to that of the driving current pulse. In FIG. 2c. this is indicated by the negatively directed pulse portion N. Both the reduction of the driving current pulse and the additional damping after the vibrator has reached its rest position. cause the vibrator frequency to be increased to the frequency of the synchronizing signal. FIG. 2d shows a case in which the deviation between the frequency of the mechanical vibrator and the frequency of the synchronizing signal or the phase difference thereof, has already grown to such an extent for example. owing to some strong rotational delay effected upon the mechanical vibrator from the outside that only a damping current pulse N will still be flowing after the rest position of the vibrator. This still further increases the degree of synchronizatron.

Of course. during operation, there may also occur cases in which the driving current pulse V comes to an overlapping with the positive pulse portion of the synchronizing signal as shown in FIG. 20. before the rest position of the vibrator. so that this driving current pulse is damped at least partly. This will then result in a reduction of the frequency or in an increase in the phase of the mechanical vibrator towards the synchronizing frequency or the synchronizing phase position respectively.

FIG. 3a shows the shape of curve of the two synchronizing signals in accordance with a further embodiment of the invention. The synchronizing signal I controls the driving current pulses while the synchronizing signal II controls the damping current pulses. The times be tween the two leading edges and between the two trailing edges are indicated by the reference C in FIG. 3a; A and B indicate the times during which driving or damping current pulses may occur respectively.

FIG. 3b shows the case corresponding to that of FIG. 2b. i.e. in which the driving current pulses V or N are not being affected by the synchronizing signal. In FIG. 3c, however. the natural frequency of the mechanical vibrator is reduced or there exists a phase deviation. The backward driving pulse N partly coincides with the positive pulse portion of the synchronizing signal I. Owing to the inventive proposal saying that neither a driving nor a damping current pulse is to be effected during the time C between the two leading edges of the synchronizing signal, the driving current pulse N is thus merely shortened.

FIG. 3d shows the case where the driving current pulse N. after the rest position of the vibrator. falls completely within the period of time between the two leading edges of the synchronizing signal, and is thus not at all effective.

In FIG. 3e the driving current pulse is shown to fall partly already within the period B of the dampingsynchronizing signal ll. thus being converted into a damping current pulse N having a direction of effect which is in opposition to the driving current pulse.

FIG. 3f. finally. shows the case where the driving current pulse. after the rest position of the vibrator. falls completely within the period B. so that the damping current pulse N appears with its maximum width.

FIG. 4 shows a simple circuit arrangement for carrying out the invention with a contact-making clock system. In the manner as known in connection with contact-making clocks. the contact K as actuated by the magnetic balance type. is arranged in series with the driving coil L. In parallel with this series arrangement there is disposed the resistor R or the series arrangement consisting of the resistor R and the diode D. This parallel connection is applied with its one end to the voltage-conducting pole of the source of supply voltage U while between the other end thereof and the zero point of the circuit there is connected the collector-emitter path of transistor T1, with the base electrode thereof being controlled by a synchronizing signal from a quartz oscillator and frequency divider 2.

In cases where the closing time of contact K and the current flux time as controlled by the synchronizing signal, coincide in the transistor T1, the driving current pulse will flow in the driving coil L while both the resistor R and the diode D are rendered ineffective. Diode D and resistor R are ineffective since the ohmic resistance of coil I- is small with respect to resistance R and the resistance of diode D. and further, since battery U drives a main current from its negative to its positive pole through the emitter collector path of transistor T and the coil and a small current through resistor R and diode D. In this case, resistor R and diode D have no influence on the driving pulse acting between the coil L and the magnet type balance system I. In this case the current flux time in the transistor T1 corresponds to the time A of FIG. 2a. It should be noted. however, that in this case, the polarity of the pulse shown in FIG. 2a must be inverted. However, if the transistor T1 is disconnected by the synchronizing signal before the contact K opens. the current direction of the current pulse as flowing in the driving coil L is reversed. because now the current flows across the resistor or across the resistor and the diode respectively, thus acting as a damping current which would thus correspond to the shape of curve shown in FIG. 2c. In this case, coil L acts as an electromotive voltage source since the magnetic system will act upon coil L, thus inducing a voltage. This voltage (see FIG. 1) now drives a current through resistor R and diode D, the direction of which is opposite to that of the above mentioned small current. This reverse current consumes energy and therefore dampens the vibrating system.

In cases where the closing time of contact K is lying outside the current flux time of transistor T1, the driving coil L is damped during the entire closing time. and the damping current pulse is permitted to flow owing to the voltage induced therein by the magnet system. Accordingly, this case would correspond to the shape of curve shown in FIG. 2b.

FIG. 5 shows a further embodiment of the circuit arrangement of FIG. 4 for practical application with a contact-making clock system. In this case. between the resistor R or the diode D and the voltage-conducting pole of the source of supply voltage U there is connected the collector-emitter path of the further transistor T2 which is complementary to transistor T1. To the base of the further transistor T2 there is applied the second synchronizing signal II from quartz oscillator and frequency divider 3 whose frequency is equal to the frequency, and whose pulse duty factor is equal to or smaller than that of the synchronizing signal as up plied to the base of transistor T1. In the case ofa different pulse duty factor there will result the further embodiment of the inventive method explained with reference to FIG. 3. Thus, in cases where the transistor TI as well as the transistor T2 are blocked simultaneously, neither a driving current pulse nor a damping current pulse can flow in the driving coil L.

FIG. 6, finally, shows another circuit arrangement for carrying out the invention with an electronic single-coil circuit for clock drives. This single-coil circuit, for example, is substantially known from the applicants earlier German Patent Application corresponding to the German Offenlegungssehrift 2 I I 023. It substantially consists of the transistors T3, T4 and T5, of the resistors RI, R2, R3, R4, and of the capacitor C, as well as of the driving coil L. In this case the transistor T3 acts as a driving transistor and the transistor T4 which is complementary thereto, acts as a control transistor, whereas transistor T5 being of the same conductivity type as transistor T4, serves as an additional transistor.

In analogy to the arrangement according to FIG. 4, the transistor Tl may now be provided for and which, in FIG. 6, is connected with its collector-emitter path between the base of the driving transistor T3 and the zero point of the circuit, while the synchronizing signal is again applied to the base thereof. In this way the base of the driving transistor T3 and the collector of the control transistor T4, during the current flux period of the transistor T1, are practically applied to the potential of the zero point of the circuit, and in the case of a synchronizing signal of corresponding polarity there will occur the same effects with respect to the driving current pulse or the damping current pulse as in the arrangement according to FIG. 4.

FIG. 6, moreover, also shows the further transistor T2 according to FIG. 5, whose emitter-collector path, across the resistor R which, accordingly, corresponds to the resistor R of FIGS. 4 and 5, is connected between the voltage-conducting pole of the source of supply voltage U and the end of the driving coil L not facing the source of supply voltage. As regards both the frequency and the pulse duty factor of the second synchronizing signal as applied to the base of transistor T2, there is applicable analogously the same as has been said in connection with explaining FIG. 5 of the drawings. If, accordingly, the pulse duty factor of the synchronizing signals applied to transistors TI and T2 are different, there will again result the mode of operation which has already been explained hereinbefore with reference to FIG. 3.

Investigations have shown that the synchronizing range in the case of clocks (watches) operated in accordance with the invention, was considerably increased as compared to clocks (watches) operated in accordance with known prior art arrangements. Moreover. the invention substantially accelerates the synchronizing process so that any occurring deviation of frequency and phase position of the mechanical vibrator from the nominal value is compensated for more speedy than in the arrangements according to the known prior art.

What is claimed is:

1. A circuit for synchronizing watches driven by a coil-magnet system, by means of a synchronizing signal having a frequency which corresponds to the frequency of the divider output of a quartz oscillator, said circuit powered by a source of supply voltage having positive and negative poles, comprising:

a source of a first synchronizing signal;

a source of a second synchronizing signal;

a drive coil having first and second terminals, said first terminal coupled to said positive pole;

a first transistor having base, emitter and collector terminals, said base coupled to said first synchronizing signal and said emitter coupled to said negative pole of the circuit;

a second transistor having a base, emitter and collector, said base coupled to said second synchronizing signal and said emitter coupled to said positive pole;

a third transistor having a base. emitter and collector, the emitter of said third transistor coupled to said negative pole of the circuit and the base of said third transistor coupled to the collector of said first transistor;

a fourth transistor having a base, emitter and collector, said collector coupled to the collector of said first transistor;

a voltage divider coupled between the collector of said third transistor and said negative pole of the circuit, the base of said fourth transistor coupled to a junction point of said voltage divider.

a fifth transistor having a base. emitter and collector, said base coupled to the second terminal of said driving coil. said emitter coupled to the emitter of said fourth transistor and said collector coupled to said negative pole of the circuit;

a first resistor coupled between the base of said fifth transistor and the collector of said second transistor; and

a capacitor coupled between said positive pole and the emitter of said fifth transistor. 

1. A circuit for synchronizing watches driven by a coil-magnet system, by means of a synchronizing signal having a frequency which corresponds to the frequency of the divider output of a quartz oscillator, said circuit powered by a source of supply voltage having positive and negative poles, comprising: a source of a first synchronizing signal; a source of a second synchronizing signal; a drive coil having first and second terminals, said first terminal coupled to said positive pole; a first transistor having base, emitter and collector terminals, said base coupled to said first synchronizing signal and said emitter coupled to said negative pole of the circuit; a second transistor having a base, emitter and collector, said base coupled to said second synchronizing signal and said emitter coupled to said positive pole; a third transistor having a base, emitter and collector, the emitter of said third transistor coupled to said negative pole of the circuit and the base of said third transistor coupled to the collector of said first transistor; a fourth transistor having a base, emitter and collector, said collector coupled to the collector of said first transistor; a voltage divider coupled between the collector of said third transistor and said negative pole of the circuit, the base of said fourth transistor coupled to a junction point of said voltage divider, a fifth transistor having a base, emitter and collector, said base coupled to the second terminal of said driving coil, said emitter coupled to the emitter of said fourth transistor and said collector coupled to said negative pole of the circuit; a first resistor coupled between the base of said fifth transistor and the collector of said second transistor; and a capacitor coupled between said positive pole and the emitter of said fifth transistor. 